三维准静载弹塑性弯曲裂纹张开位移  

THE THREE DIMENSIONAL CURVED ELASTICITY-PLASTICITY CRACK TIP OPENING DISPLACEMENT UNDER QUASI-STATIC LOAD

作　　者：杨大鹏[1,2,3] 王书勤 周超 晋玉霞[2] 杨新华[1] YANG DaPeng;WANG ShuQin;ZHOU Chao;JIN YuXia;YANG XinHua(School of Civil Engineering & Mechanics,Postdoctoral Mobile Station of Mechanical Department,Huazhong University of Science and Technology,Wuhan 430074,China;Department of Material Engineering,Zhengzhou Technical College,Zhengzhou 450121,China;School of Naval Architecture & Ocean Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Department of Automotive Engineering,Henan Traffic Senior Technical School,Zhumadian 463002,China;Teaching Department,National Defense Science and Technology School of Zhengzhou City,Zhengzhou 450000,China)

机构地区：[1]华中科技大学土木工程与力学学院力学系博士后流动站,武汉430074 [2]郑州职业技术学院材料工程系,郑州450121 [3]华中科技大学船舶与海洋工程学院,武汉430074 [4]河南省交通高级技工学校汽车工程系,驻马店463002 [5]郑州市国防科技学校教学部,郑州450000

出　　处：《机械强度》2019年第2期442-446,共5页Journal of Mechanical Strength

基　　金：国家自然科学基金重大研究计划项目(91016026);河南省博士后科研项目(166053)资助~~

摘　　要：主要研究准静载荷作用下的三维弹塑性弯曲裂纹尖端的张开位移问题。综合考虑了准静作用应力,三维塑性区域边界上正应力与剪应力,利用二阶摄动方法计算了三维弹塑性弯曲裂纹尖端的张开位移。用数值解法计算出三维弹塑性弯曲裂纹尖端张开位移,作图分析了三维弹塑性弯曲裂纹尖端张开位移与三维裂纹体几何尺寸之间的变化关系。三维弹塑性弯曲裂纹尖端张开位移随着三维裂纹体厚度的增大而减小,随着三维裂纹体厚度的均匀增大,三维弹塑性弯曲裂纹尖端张开位移尺寸不断减小,减小的幅度越来越小,最终趋于平面应变状态下的弹塑性弯曲裂纹尖端张开位移尺寸。当三维裂纹体几何尺寸相同时,三维弯曲裂纹尖端张开位移尺寸随外载荷的不断增大而逐渐增大。建立了一个计算三维弹塑性弯曲裂纹尖端张开位移尺寸的崭新理论模型。In this article, three dimensional elastic-plastic curved crack tip opening displacement under quasi-static loads has been mainly studied, and three dimensional curved crack tip opening displacement has been calculated as a practical application of a second order perturbation method, where the effects of quasi-static applied stresses and quasi-static normal and shear stresses on the boundaries of plasticity area are synthetically taken into considerations. Three dimensional curved elastic-plastic crack tip opening displacement has been calculated by numerical solutions, diagrams have been constructed to analyse the transformation relationships between curved crack tip opening displacement and three dimensional crack body geometrical measurement. Curved crack tip opening displacement will decrease when three dimensional crack body thickness increases. When crack body thickness increases evenly, three dimensional curved crack tip opening displacement will continuously decrease, furthermore, the decrease extent will be more and more slightly, and tend to plane strain state ultimately. Curved crack tip opening displacement will increase when external loads increase with the same crack body thickness. A new theoretical model where curved crack tip opening displacement was calculated has been established in three dimensional crack body.

关 键 词：三维裂纹体 弯曲裂纹 张开位移 准静作用应力 二阶摄动方法 

分 类 号：TB301[一般工业技术—材料科学与工程]